Cheating on a test and getting caught. It was so dumb because I didn't even have to cheat there was hardly anything to learn. But my lesson was learned.
Probably Watkins Glen New York. (I'm from Canada) Got to see a race on a road course and that was pretty awesome! Even got within 6feet of a famous driver! Unfortunately I've never been to another country besides the USA otherwise my answer would have probably been different.